Electric Vehicles

AeroVironment, Inc. and the U.S. Department of Energy’s Pacific Northwest National Laboratory (PNNL), managed by Battelle, announced a commercial license agreement for a technology that supports widespread adoption of plug-in electric vehicles (PEVs) by helping to stabilize the electrical grid -- the network of electricity generation, transmission, and distribution that powers the nation.

The technology may result in lower-cost electricity for plug-in vehicle drivers due to the grid support functions provided during vehicle charging, according to AeroVironment. The company will use a portion of the licensed PNNL technology in a new prototype version of its Level II charging systems.

“We are working to broaden the adoption of plug-in vehicles to help achieve America’s environmental, economic and energy security goals,” said Wahid Nawabi, AeroVironment senior vice president and general manager of its Efficient Energy Systems (EES) business segment. “While easily and reliably recharging PEVs, this grid-friendly charging system will also improve grid performance, turning PEVs and their chargers into a valuable solution to a broader challenge.”

The licensed PNNL technology can help stabilize the electrical grid by continuously monitoring the grid’s alternating current (AC) frequency and varying the vehicle charging rate in response. Additionally, in the event of a rapid drop in grid frequency, the charging system stops charging, providing a grid “shock absorber,” according to AeroVironment. Such rapid frequency drops, while small in overall magnitude, indicate that a fault condition has occurred somewhere on the grid and that there is an imbalance between load and electricity generation. By reducing load, the system can be rebalanced.

Conventional power plants make continual power generation adjustments based on precisely measured grid frequency in order to maintain a nearly constant frequency of 60 cycles per second. As renewable generation sources such as wind and solar grow in overall share, the overall frequency-responsive generation capability provided by conventional power plants is gradually decreasing. AeroVironment and PNNL’s frequency-responsive technology brings this same grid frequency support capability to PEV charging stations.

AeroVironment and PNNL share the vision that with millions of plug-in vehicles charging at any given time, modulating the aggregate charging rate of PEVs can help control grid frequency and support the integration of variable renewable generation sources, such as wind and solar.

“These technologies will result in a triple-win,” said Dr. Alec Brooks, chief technology officer of AeroVironment’s EES business segment. “First, reducing the cost of integrating variable renewable generation reduces electricity costs for all ratepayers. Second, plug-in cars can be powered by renewable generation that might not have been possible to add to the grid without the charging rate flexibility offered by vehicles and this technology. Third, the reduced cost of electricity to plug-in vehicle drivers will further improve on the cost advantage of driving on electricity as compared to gasoline.”

“Vehicle charging infrastructure is important for the market adoption of electric vehicles and plug-in hybrid electric vehicles,” said Dan Ton, DOE’s program manager of Smart Grid Research and Development. “We need charging stations and we need them to be intelligent in order to work with smart vehicles and smart grid infrastructure to avoid potential strain on the grid and to provide flexible billing transactions for energy and grid services.”

Prototypes of the new AeroVironment charging system are available immediately for beta testing. The prototypes include Bluetooth wireless connectivity for data streaming and local control functions.

Working in partnership with the nonprofit carsharing service Hourcar and Xcel Energy, the city of St. Paul, Minn., applied for federal funding through the Congestion Mitigation and Air Quality Improvement Program.